Target Shooting Glasses for under £5

As I get older, I find it increasingly difficult to focus on the foresight of a pistol and keep the rear sight and target sharp. It's a common problem, and the usual remedy is to stop down the aperture of the aiming eye by looking through an orthoptic (allowable under UIT rules), which is simply a peephole similar to the iris of a camera. On a target rifle, this peephole is mounted in the rear sight; but on a pistol, it has to be attached to you! It can also help with iron sights on a rifle. The problem with these orthoptic shooting glasses is the price; and after paying out less than £100 for a Gamo Compact pistol (1999), the last thing I wanted at that time to do was spend a similar amount on shooting glasses. The reason for the expense of ready-made (usually German) orthoptic shooting glasses seems to be the exceptional quality, strength and lightness, together with super-adjustability, with everything being held by sliders and knurled screws. The adjustable iris is a very complex piece of kit, but all you really need is a spectacle frame holding an opaque disk with a small hole (iris) for the aiming eye, and a similar solid disk as an occluder to cover the other eye. Replaceable disks with different size holes will give a range for different lighting conditions; and if you make the frames to suit your head, you only need to adjust the position of the disks.
My design uses model makers' fine round and square section brass tubing, and the important property of this stuff is that each tube size slides snugly inside the next size larger. Gentle distortion to the outer tube before fitting will effect a tighter sliding fit, and this principle is used throughout to avoid the need for knurled screw adjusters. What you need is about four inches of square brass tube about 5/32" outside dimension, about 12" of the next square size down, and another 12" of round tube that slides inside the smaller square tube. Finally, dig out an old pair of plastic sunglasses to make a nose bridge. Some 2mm screws or rod will be needed for the hinge pins, and a few bits of sheet brass and some steel rod that fits inside the round tube to make the nose bridge supports. Simple tools are sufficient, but a small electric multi-tool will make life much easier for cutting and polishing. I also used a pencil gas torch and some soft silver solder and acid flux. You should take normal precautions when using these materials, especially eye protection. Cut a length of the smaller size of square tube equal to the width of your head. Heat the center of the tube with the torch until it almost glows, and let it cool. The brass will now bend easily into a shallow "V" to suit your forehead. Drill a 2mm (5/64") hole close to each end to take the hinge pins. Then, cut some more tube about two inches long for the side arms. Cut two 3/4" lengths of the larger tube and slide them onto each side of the frame to provide horizon tal movement for the iris and occluder.
Each hinge is made from a 3/4" length of the larger tube with one side cut out to make a channel section. Drill a 1.5mm (1/16") hole through both pieces halfway along and tap out to 2mm so that they will pivot when screwed through the clearance holes in the frame ends. File the frame ends round so they pivot freely. Position the hinges so they are in line with the frame, then insert the side arms so they lie parallel with each other-just like regular glasses. You should now solder the side arms into the hinges and then trim off the ragged end of the hinges to make them neat. This gives a very strong hinge. Solder a 3/4" length of the smaller square tube vertically to each slider to take the iris and occluder, which are made of one-inch disks of brass soldered to lengths of the round tube. The disks will now slide in both directions. Try disks with lmm (3/64"), 1.5mm (1/16") and 2mm (5/64") holes-and painted matte black. The nose piece is made and shaped according to your own face shape, and is made from the center cut out of the old sunglasses, with two wire rods, heated and pressed into the lens grooves. The rods are positioned bent and slid into tubes soldered onto the frame centers. The frames should be held up high and away from the brow. The ear pieces are made from the round tube, which is bent to fit round the ears and slid into the side arms, where they can be soldered or simply crimped to a tight fit for adjustment. Flatten the ends and apply heat shrink tubing for comfort.
Finally for additional protection for plinking or rimfire use, the one-piece lens from a pair of safety goggles can be removed, trimmed to shape and screwed to the inside of the frame. If you really have a bad eyesight defect, next time you have the plastic lenses replaced in your regular glasses, ask for your old lenses back, carefully file the correct one to shape and fix to the iris disk. A bit of imagination could yield all sorts of lens and filter holders.
This article written by me in 1999 first appeared in Airgun Revue #5 (1999) published by GAPP Inc. 4614 Woodland Road, Ellicott City, Maryland 21024-6329
Copyright © 1999 GAPP, Inc and © 2006 Jarviser's Workshop, all rights reserved including the reproduction in whole or in part in any form